Mästarnas mästare (idiomatic translation "Champion of Champions") is a Swedish reality competition show which each season feature a number of former athletic stars who all became "masters" of their individual sports. In the show the athletes competes against each other in a number of different athletic challenges. All contestants have in common that they have won at least one gold medal in their respective sports and they have all ended their careers. The show has been broadcast on SVT since 2009.
https://en.wikipedia.org/wiki/M%C3%A4starnas_m%C3%A4stare